Conventional internal combustion engines are provided with a number of different operating mechanisms for controlling inlet and outlet valves for the engine cylinders or in the case of fuel injected engines for controlling the injectors. Usually such mechanisms take the form of cam shafts, rockers, return springs or other mechanical actuating elements. Such mechanism suffer a number of disadvantages and limitations including in the case of valved engines poor valve cooling, poor lubrication, a lack of ability to maintain alignment of the valves with their seats, poor control over movement of the valve and an excessive amount of power which is required to overcome the valve seating springs.
Particular disadvantages associated with fuel injectors include lack of flexibility of injection timing, excessive mechanical components in the injector drive train, an excessive amount of power wastage in operating the injectors and their drive train and a lack of ease of assembly and removability of the injectors and associated drive train from the engine during maintenance.
Conventional internal combustion engines usually also include reciprocating pistons which are coupled to a crank shaft via piston rods, however, this form of mechanical connection has limitations resulting in limitation of transmission of usable energy from the piston to the crank shaft caused by changes of the lever arm at the crank shaft from zero at the start of the stroke through a maximum at approximately half stroke to zero at the end of the stroke. Further disadvantages arise because of side thrust friction losses causing cylinder and piston wear induced by thrust angles of the connecting rods relative to the cylinder bore centre line during rotation of the crank shaft. Lack of flexibility in the control of the rate of expansion of the gases of combustion also occurs due to utilization of a rotating crank shaft rigidly attached to the reciprocating pistons by connecting rods consequently leading to a considerable loss in the recovery of usable energy from the gases of combustion.